However it opens the door for genetically modified fruit and vegetables to be sold in British supermarkets.

Currently the European Union bans the use of commerical crops because of opposition across Europe.

Under the new rules each European country will be allowed to decide for itself whether or not to grow GM, once it has been ruled safe by the European Food Safety Authority (EFSA), the EU’s food safety body.

The deal has been engineered by the British government who are fed up that GM trials continue to be blocked by Germany, France and Italy.

Last week Lord de Mauley, the environment minister, told MPs that genetically modified produce are a "key agricultural technology for the 21st century".

He told the science and technology select committee that it will help "undo the logjam" in approvals for genetically modified crops at European Union level.

However, he said he was "disappointed" that the legislation will allow other European nations to make decisions to ban GM crops which are "not based on scientific evidence".

It is feared that farmers would be persuaded from growing GM because there would be no export market.

Genetically modified crops are currently being trialled at Rothamsted Research, Hertfordshire and Norwich in Norfolk, but they will not be sold commercially. Wales and Scotland are opposed to the use genetically modified crops and will not be growing anyway.

Genetically modified maize and oilseed rape were the most likely crops to be grown in this country, alongside potatoes which require lower levels of pesticides. They are likely to take several years to gain approval from regulators.

GM ingredients are already in food available on supermarket shelves, mostly in cooking oils containing GM soy or oilseed rape. However these will be labelled, according to EU law. Most supermarkets have banned GM ingredients in their own-brand products.

Waitrose continues to require non-GM feed for poultry, eggs and lamb. In April 2013, Tesco, the Co-Op and Marks and Spencer announced they no longer required poultry to be fed on GM-free feed, following similar decisions by Morrisons (March 2012) and Asda (September 2010).

Genetically modified crops are plants where the DNA has been modified to introduce a new trait such as the ability to withstand drought or insects. Scientists "cut and paste" a gene from another organism with these capabilities and insert it into the genome of the plant.

Sir Mark Walport, the government’s Chief Scientific Advisor recommended that Britain should begin production after finding GM crops were not only safe, but were likely to be more nutritious than current crops.

GM crops are already widely used in the US, Canada, Brazil, Argentina and India. Around 85 per cent of all corn crops in the US are now GM.

But campaigners fear that disrupting the natural DNA of a plant could affect biochemical pathways and lead to the production of unexpected toxins which could be harmful to health.

There are also concerns that GM crops may have the same impact as an invasive alien species, damaging ecosystems. In 1999 it was suggested that GM maize, which had been tweaked to fight pests, was killing Monarch butterflies.

Pollinating plants could also transfer modified genes to weeds, boosting their resilience and making them difficult to control.

Such 'super-weeds' were discovered in Canada where cross-pollination had occurred between GM oilseed rape plants and grasses making them immune to herbicides.

A study in 2012 suggested that herbicide-tolerant maize caused tumours and early death in rats but the paper has since been retracted.

Opponents also claim that sheep and goats are dying in India from eating genetically modified cotton.

A review of 24 studies of the health impacts of GM found there were no significant differences between GM and non GM crops.

Many scientists believe the benefits outweigh the risks. Farmers have been changing the genetic make up of plants through breeding since agriculture began to improve yields and make larger and hardier specimens.

Currently GM crops must be passed by the EFSA and then be approved by the Britain’s Advisory Committee on Novel Foods and Processes (ACNFP) – an independent body of scientific experts. None have ever been licenced for commercial use.